Ammonia is one of the most dangerous gases. In this post, I will explain what ammonia is, why it is dangerous, and how to detect it.
What is ammonia gas?
Ammonia, with the chemical formula NH3, is a colorless, alkaline gas with a pungent, urine-like smell. It’s highly soluble in water, forming ammonium hydroxide, which is hazardous due to its corrosive nature.
Despite its risks, ammonia is widely used in industries as fertilizer, refrigerant, and even in the production of explosives.
Why is ammonia harmful to humans?
Ammonia is dangerous because of its corrosive properties. When inhaled or exposed to the skin, it can cause severe burns to membranes, eyes, and respiratory organs.
Even low concentrations can irritate, while high levels can result in asphyxiation. This duality of being both beneficial and hazardous makes proper detection crucial in industrial and safety applications.
How to Detect Ammonia Gas?
Detecting ammonia requires precision, as even minor leaks can pose risks. There are three main types of sensors for ammonia detection.
Electrochemical Sensors
These are the most commonly used for ammonia detection due to their cost-effectiveness. While not as accurate as semiconductors, they offer reliable detection for most applications.
Semiconductor Sensors
These sensors are highly accurate and sensitive but tend to be more expensive. Industries requiring precision often opt for this type.
PID Sensors (Photoionization Detectors)
While they can detect ammonia, these sensors often have a high correction factor, making them less reliable. Based on experience, they are not recommended for ammonia detection.
Types of Ammonia Gas Detectors
Portable Ammonia Gas Detectors
Portable detectors are ideal for personal safety and monitoring small-scale environments. When selecting a portable device:
- Choose one with electrochemical sensors for cost efficiency.
- Ensure it has a clear display and audible alarms for easy use in emergencies.
- Verify that it meets safety certifications like ATEX or UL standards.
Fixed Ammonia Gas Detectors
For continuous monitoring in industrial settings, fixed detectors are essential. When choosing one:
- Consider the area coverage and placement.
- Opt for devices with real-time monitoring and integration capabilities with other safety systems.
- Check for compatibility with industrial protocols (e.g., Modbus, BACnet).
FAQ: How to Detect Ammonia Gas?
What is the acceptable exposure limit for ammonia?
The permissible exposure limit (PEL) is twenty-five ppm (parts per million) over eight hours, as defined by OSHA.
What should I do if ammonia is detected?
Evacuate the area immediately, ventilate the space, and follow emergency procedures. Use protective equipment when re-entering the site.
Can ammonia gas be detected by smell?
Yes, ammonia has a strong smell, but relying on smell alone is unsafe, as olfactory fatigue can occur.
How often should ammonia gas detectors be calibrated?
Calibration should be done at least every six months or as recommended by the manufacturer to ensure accuracy.
